After proving himself the undisputed champion of butt-kicking on Sakaar in Thor: Ragnarok (with a little help from the obedience disk embedded in Thor’s neck), Hulk gets a bit of an attitude adjustment in the opening act of Avengers: Infinity War after being soundly defeated in hand-to-hand combat by Thanos; the Mad Titan not only knocks Hulk unconscious, he also draws blood.

Thor put up a good fight when he faced Hulk in the Grandmaster’s Contest of Champions (and certainly might’ve done plenty of damage to his “friend from work” with those lightning strikes if the Grandmaster hadn’t intervened), but this is a beating unlike anything the Hulk has faced before, and it’s clear that Thanos laying the smack down on him is enough to shake the Green Goliath’s confidence in a major way.

After his first fight with Thanos on the Asgardian refugee ship, Hulk isn’t seen again in Infinity War, with Bruce Banner spending the rest of the movie unsuccessfully trying to convince his alter ego to come out and join the fray. (Hulk literally says "no" like a child throwing a tantrum at one point when Bruce tries to force him out.) And it’s apparently not just Thanos that has Hulk scared - he won’t even emerge to fight the Mad Titan’s “children,” Ebony Maw and Cull Obsidian, alongside Iron Man, Doctor Strange and Wong in New York.

This adds an interesting dimension to Bruce’s relationship with Hulk; for the entirety of the character's existence in the MCU, the movies have explored Banner's struggle to restrain the monster inside him - even telling Captain America, "I'm always angry" in the very first Avengers, implying that Banner basically lives his life in a constant state of readiness to change into the Hulk.

But as Mark Ruffalo told IGN in 2017, Thor: Ragnarok was the start of a specific character evolution for Bruce and Hulk that would carry through to Avengers 4. "The anger is no longer the only reason that he turns into the Hulk. So now we have this other thing going on between them that will carry out through the next two movies. This is the beginning of a three-movie arc," he explained. "Kevin [Feige] brought me in and he said, 'What would you do if you could do a standalone Hulk movie?' I said, 'I think it should be this, this, this, and this, and it should end like this.' And he said, 'How about if we do that -- love that -- let's do that starting with Thor 3 and end in Avengers 4, and we'll use those three movies to basically do a standalone Hulk movie. How about that?' I was like, 'That sounds great.'"

While Thor: Ragnarok raised the possibility that, because Hulk had been in control for so long, another transformation might permanently trap Banner and leave Hulk on the outside forever, Infinity War inverts that dynamic, exploring the idea that the Other Guy is far more than just the rage machine others assume him to be - he's equally capable of feeling fear (and apparently pain), even if it takes a Titan to threaten him.

It's fascinating that we don't see Hulk again following his fight with Thanos (even though the trailers shamelessly misled us and showed Hulk running into battle alongside Captain America, Black Widow, and the Wakandan army), meaning that Bruce has to face off with the Black Order and their outriders in Tony's old Hulkbuster armor, even when, logically, Bruce is far more susceptible to damage (and therefore death) than Hulk is.

This builds on the vulnerability that Hulk showed in Ragnarok, where we saw his frustration and fear of isolation after reconnecting with Thor. Despite Bruce spending his life trying to push people away to protect them, it's clear that he craves connection and companionship, and those fears are brought to the surface when he's finally faced with the reality of his mortality. Let's face it, death has never been a real concern for the Hulk - in the first Avengers movie, Bruce admitted that he tried to commit suicide once by trying to shoot himself, but the Other Guy spit the bullet out. This is a creature that thinks he's indestructible, so it makes sense that almost being beaten to death would affect the Hulk's confidence.

Obviously, the most pressing issue for the team going into Avengers 4 will be trying to undo Thanos' cosmic genocide, but Infinity War also sets up some intriguing possibilities for Bruce's ongoing character arc - can he and the Other Guy actually come to a place of true partnership, rather than one wrestling for control over the other? If that's the case, we could see a very different Hulk (and a very different life for Bruce) when the Strongest Avenger finally decides to reappear.